We seek to extend our understanding of why couples divorce or stay together by studying the determinants of wives and husbands initiating divorces. The innovation of our study is classifying divorces according to whether the wife or husband initiates it, as revealed by who ex-spouses report to have wanted the divorce more, and analyzing the distinct determinants of women leaving men and men leaving women. The study uses all three waves of the National Survey of Families and Households. We draw upon exchange theory in sociology, the "new home economics," and interdisciplinary theorizing on gender. One goal of our study is to assess whether having better alternatives outside the marriage makes a partner more likely to initiate divorce, particularly if s/he is somewhat unhappy in the marriage. Having higher earnings (which facilitate support of oneself, one' s children, and possibly a new family) should affect alternatives outside the marriage and encourage initiation of divorce. Better health (e.g., not having a physical or mental disability) should improve one' s ability to live on one' s own and prospects on the "marriage market," and thus make initiating divorce more likely. We will also assess whether a partner receiving more benefits from a spouse is less likely to initiate divorce. These benefits may include income from the spouse' s earnings, household work, emotional support, treatment perceived as fair, and the ability to rear children in an "intact" family. We also propose to assess gender differences in the effects of these factors; for example, if youth is more prized when evaluating women as potential mates, then age will deteriorate women' s outside "marriage market" alternatives more than men' s, and women' s inclination to initiate divorce will decline faster with age than men' s. We also seek to understand why women are reported by both men and women to be the initiators in a majority of divorces. The analysis will use competing-risk event-history models to predict wives' or husbands' initiation of divorce, each relative to the alternative of the marriage persisting. We will employ various strategies to deal with missing data and with measurement problems such as cases where the two ex-spouses disagree on who wanted the divorce more. Our proposed strategies include imputation of missing data and latent class models. [unreadable] [unreadable]